There often arises a need to detect the existence, rate and quantity of dry solids in small diameter process piping (e.g. the flow of catalysts fed into reactor vessels), without obstructing or intruding into the flow path.
The present invention provides a non-intrusive means for monitoring the flow of such dry solids by directing flow through a friction sensitive electrode, equal in diameter to the process piping, and which detects the presence of solids by virtue of electrical charge transfer, which is created within the inner diameter of the electrode as a result of frictional contact of the solids with the electrode.
While such a friction sensitive electrode is capable of detecting the particulate matter, the sensitivity of such an electrode can be rendered meaningless by the interference of outside sources of electrical generating current, such as internal movement or the intrusion of external electric fields.
At present, there is no reliable non-intrusive means of detecting the flow of dry solids in small diameter (under 0.500" diameter) process piping.